Construction and application of piston-valves.



No. 697,840. Patented Apr. I5, l902.

J. H. R. HEAD.

CONSTRUCTION AND APPLICATION OF PISTON VALVES.

(Application filed Apr. 26, 1901.)

(No Model.)

llirnn rates JOSEPH HENRY RENDER HEAD,

ATENT Fries.

OF SOUTH SHIELDS, ENGLAND.

CONSTRUCTION AND APPLICATION OF PISTON-VALVES.

SPECIFICATION forming part of Letters Patent No. 697,840, dated April15, 1902. Application filed April 26, 1901. Serial No. 57,655. (Nomodel.)

To [LZZ 1071,0722, it may concern.-

Beit known that I, JOSEPH HENRY RENDER HEAD, a subject of the King ofGreat Britain and Ireland, and a resident of South Shields, in thecounty of Durham, England, have invented certain new and usefulImprovements in the Construction and Application of Piston-Valves; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

The objects of this invention are to obtain the many advantages of suchvalves, as perfeet tightness against leakage of gases or fluids underpressure, the absence of friction, and consequently of wear, simplicityof construction and fitting, and non-liability to leakage by beingfouled by grit and dirt getting on the seats of miter or similardirectseating valves. Valves so constructed and applied are speciallyadapted for all cases where such advantages are of primary importance,as where there are many objections to other forms of valves, as miter orsimilar direct-seatin g valves. As they have been specially designed forpressure or vacuum brakes on railway-vehicles, I will so illustrate anddescribe them.

Figure 1 shows in sectional elevation a piston-valve sliding in a tubeapplicable alternatively for pressure and vacuum brakes, as the case maybe, such as are adapted to enable an alarm to be sounded and the brakesgradually applied on an emergency by a passenger in any compartment ofeach carriage forming a train. Fig. 2 shows, enlarged for clearness, thepiston, with one mode of packing it. Fig. 3 shows an illustration oftheir application to What is called the quick-acting triple valve of the\Vestinghouse brake system and replaces a direct-seating valve, withwhich great difficulty is found in keeping the faces free from leakagecaused by being fouled by grit, dirt, or the like on their faces.

The figures all are about full natural size except Fig. 2, which ispurposely enlarged; but only those parts are shown which are necessaryto illustrate the piston-valve, its construction, and operation, theothers being merely outlined.

Referring to Fig. 1, A is the tube in which the piston B slides to openor close the ports 0 through and around the tube as the piston isactuated by any suitable mechanism-as a cord or chainby lovers from anycompartment, on either side of the compartment, by a passenger in caseof emergency opening either the pressure or vacuum valve, as the casemay be, and releasing the pressure or admitting the atmosphere throughthe ports 0 to destroy the vacuum, simultaneously sounding a whistle orgong at X to give an alarm-signal and gradually applying the brakes. Therod 13' of the piston B works through guides and is furnished with aspring E, (shown shortened for want of space,) tending to return it tothe closed position when the guard has set back the mechanism to itsnormal position. The full lines show the piston when the ports 0 admitair under pressure and the dotted lines when it has been moved downwardto close the ports 0 to the atmosphere entering through the cover, as inthe case of vacuum-valves. Fig. 1 shows a pressure-brake valve in whichin its normal or closed position the piston B is as shown by dottedlines, the ports 0 being closed against the air entering below from thetrain-brake pipe; but the communication mechanism having been operatedby a passenger in an emergency the piston moves into the position shownby full lines, causing the air to pass through the ports and into theatmosphere, sounding an alarm at the same time through a Whistle or gongat X. With vacu urn-brakes the positions are reversed, the piston beingnormally as in full lines and when operated having moved downward to theposition shown by dotted lines, when air from the atmosphere entersthrough openings in the cover and passes through the ports 0 anddownward through ports provided below (not shown) into the train-brakepipe, destroys the vacuum, sounds an alarm, and applies the brakes.

. Fig. 2 shows an enlarged section of one of the pistons and showing onleft-hand side one method of fixing the cupped valve, of

leather or other suitable flexible material, and on the right-hand sideanother form of washer G. The cupped packing-leather F is kept in shapeand tight by a cupped washer G, secured on the piston-rod by a nut G andbya 4o der.

jam-nut G This cupped washer G is in one case perforated all around bysmall holes H, by which the pressure of air has access to the back ofthe cupped packing-leather, so as to 5 be pressed firmly against theinside of the tube A.

Referring now to Fig. 3, the drawing shows a piston-valve constructedaccording to my invention to exactly fit into the seat of the to usualdirect-seating valve, which is found very liable to leakage. A is thetube, with ports C; B, the piston sliding therein to open or close saidports and being packed with cupped leather. The piston-rod B extends I5upward and is guided in a box formed on a piston above, which actuatesit to open the ports 0, and extends downward surrounded by a springE,inclosed in a case, to return the piston to its normal position. Thisspring also controls the miter-valve Cb, which is in communication withthe train-brake pipe by the cock I) when so operated. In a cylinder 0,open at one end, is a piston d, to the top face of which air underpressure is admitted when a slide-valve on the face 6 is moved into acertain position, and this valve also opens a port f, in communicationwith the auxiliary reservoir of air under high pressure, which enters atg and passes to the brake-cylinder at h.

At the same time the air from the reservoir enters the port c' above thepiston in the cylinder c and forces it down upon the pistonrod B, movingthe piston, so as to open the ports 0 in the tube A, when the air underpressure passes through the ports and into tuated on its face, whenquick action is required, by a piston 70 in a cylinder Z by air from themain brake-pipe through the cock I) and by a passage m behind the piston70 (through a perforated disk 47.) and is thus instantlymoved the fullstroke in its cylinder Z, correspondingly moving the slide-valve to itsfull extent and applying the brakes, as described.

What I claim is- 1. In a valve mechanism, the combination with aperforated cylinder provided with an inlet and outlet for fluid underpressure, of a piston provided with a cupped packing-ring, a perforatedcupped Washer fitting in said packing-ring for admitting pressure behindsaid packing-ring, the said packing-ring having its free edge level withthe top edge of the perforated washer to prevent buckling of thepacking-ring when passing the perforations in said cylinder, and meansfor operating said piston for controlling the delivery of fluid underpressure through the perforations in said cylinder.

2. In a quick-acting valve mechanism, the combination witha supply-pipe,and a checkvalve opening from said supply-pipe; of a perforated cylinderarranged in line with said check-valve, a piston in said cylinderadapted to pass over said perforations, a piston-rod extending both waysfrom said piston, a second cylinder in line with the first cylinder, anda second piston in said second cylinder, connected with the firstpiston, a spring press= ing at one end upon the first piston and at theother end upon said check-valve, and means for admitting fluid underpressure, from said supply-pipe to the second cylinder and piston tooperate the first piston, substantially as described.

3. In a quick-acting valve mechanism, the combination with asupply-pipe, and a checkvalve opening from said supply-pipe; of aperforated cylinder arranged in line with said check-valve,a piston insaid cylinder adapted to pass over said perforations, a packing-ring onsaid piston and means for admitting pressure behind said packing-ring, apiston-rod extending both ways from said piston, a second cylinder inline with the first cylinder, and a second piston in said secondcylinder, connected with the first piston, a spring pressing at one endupon the first piston and at the other end upon said check-valve, andmeans for admitting fluid under pressure from said supply-pipe to thesecond cylinder and piston to operate the first piston, substantially asdescribed.

JOSEPH HENRY RENDER. HEAD.

\Vitresses:

WILLIAM DAGGETT, I. J. DANSON.

